Linozostis or parthenion was discovered by Mercury, and so many among the Greeks call it “Hermes’ grass”, but all we Romans agree in calling it mercurialis. There are two kinds of it, the male and the female, the latter having the more powerful properties. It has a stem which is a cubit high and sometimes branchy at the top, leaves narrower than those of ocimum, joints close together and many hollow axils. The seed of the female hangs down in great quantity at the joints; while that of the male stands up near the joints, less plentiful, short and twisted; the female seed is loose and white. The leaves of the male plant are darker, those of the female lighter; the root is quite useless and very slender. It grows in flat, cultivated country. A remarkable thing is recorded of both kinds: that the male plant causes the generation of males and the female plant the generation of females. This is effected if immediately after conceiving the woman drinks the juice in raisin wine, or eats the leaves decocted in oil and salt, or raw in vinegar. Some again decoct it in a new earthen vessel with heliotropium and two or three ears of corn until the contents become thick. They recommend the decoction to be given to women in food, with the plant itself, on the second day of menstruation for three successive days; on the fourth day after a bath intercourse is to take place. Hippocrates has bestowed very high praise on these plants for the diseases of women; no medical man recognises its virtues after this fashion. He used them as pessaries for uterine troubles, adding thereto honey, or oil of roses or of iris or of lilies, also as an emmenagogue and to bring away the after-birth. The same effects, he said, resulted from taking them in drink and from using them for fomentations. He dropped the juice into foul-smelling ears, and with the juice and old wine made an embrocation for the abdomen. The leaves he applied to fluxes from the eyes. A decoction of it with myrrh and frankincense he prescribed for strangury and bladder troubles. For loosening the bowels, however, or for fever, a handful of the plant should be boiled down to one half in two sextarii of water. This is drunk with the addition of salt and honey, and if the decoction has been made with a pig’s foot or a chicken added, the draught is all the more beneficial. Some have thought that as a purge both kinds should be administered, either by themselves or with mallows added to the decoction. They purge the abdomen and bring away bile, but they are injurious to the stomach. Their other uses we shall give in the appropriate places.

1548 William Turner The names of herbes in Greke, Latin, Englische, Duche, and Frenche (E.D.S.) 53 Mercurialis is called… in englishe Mercury… . The herbe whiche is communely called in englishe mercury hath nothyng to do wyth mercurialis.

1607 Edward Topsell The history of foure-footed beasts and serpents (1658) 390 If you take white Hellebor, and the rindes of wilde Mercury… and lay them in the Mole-hole… it will kill them.

The euphorbiaceous plant Mercurialis annua. Also baron’s, boy’s, French, garden, girl’s, maiden mercury. According to Britten and Holland, the baron’s or boy’s is the female and the girl’s the male mercury.

1578 Lyte Dodoens 78 Phyllon… . The male is called arrenogonon, whiche may be Englished Barons Mercury or Phyllon, or Boyes Mercury or Phyllon. And the female is called in Greeke qhlugonon: and this kinde may be called in English Gyrles Phyllon or Mercury, Daughters Phyllon, or Mayden Mercury.

The male of either of two plants of the genus Mercurialis, M. tomentosa and M. annua, formerly supposed to have the property of inducing the generation of female children.

1578 H. Lyte tr. R. Dodoens Niewe Herball i. lii. 78 Phyllon… The male is called ἀρρενογόνον, whiche may be Englished Barons Mercury or Phyllon, or Boyes Mercury or Phyllon. And the female is called in Greeke θηλυγόνον: and this kinde may be called in English Gyrles Phyllon or Mercury, Daughters Phyllon, or Mayden Mercury.